Backwash flushing filter

ABSTRACT

An inline backwash, flushing filter assembly comprising a header assembly, a rotatable valve assembly, and a filter element assembly disposed within a filter housing assembly. In operation, the controller moves the turn knob of the rotatable valve assembly a one-quarter turn which results in the reversal of fluid flow through the assembly to periodically back flush the filter utilizing fluid from the system inlet. Debris removed from the filter element during the backwash process are immediately discharged from the system through a drain port. Simultaneously, the hydraulic shearing mechanism of the backwash process dislodges and drains debris which may have accumulated on the screen and at the bottom of the lower filter assembly during normal filter operations. The controller then returns the filter assembly to filtration operation by a reverse one-quarter turn of the turn knob of the rotatable valve assembly.

BACKGROUND OF THE INVENTION

1 Technical Field

The present invention relates to an apparatus and method for improvingthe cleaning operation of an inline filter and, more specifically, forthe backwash and flushing of the filter element and filter assemblywithout taking the filter assembly offline for a prolonged period anddoes not require any special tools or skills to operate.

2. Description of Related Art

Filters are commonly used to remove particulates and undesired solidsfrom a fluid medium. A common filtration process involves passing afluid through a filter medium. Solids are retained on the filter medium,while the fluid passes through the filter medium and continues downstream. However, as solids begin to accumulate on the filter media, thedifferential pressure across the filter medium increases andconsequentially the fluid flow rate decreases. Likewise, the solidsretained on the filter may slough due to gravitational force and beginto form a sediment which collects at the lower end of the filterassembly which further decreases the efficiency of the filtrationsystem.

In order to return the filter and the system to peak operatingefficiency, the solids which are retained by the filter must be removedfrom the filter, along with the sedimentation located at the bottom ofthe filter assembly. A common method of filter particulate removal isknown as “backwashing” wherein the filter is taken offline, and the flowof fluid through the filter element reversed. The principal ofhydrodynamic shear removes the accumulated solids from the filter media.These solids which have now become suspended in the backwash fluid arethen directed to a waste drain. Depending on the location of the wastedrain port located on the filter assembly, the sediments which havecollected at the bottom of the filter assembly either remain or inhibitthe flow of the backwash waste water. As such, the lower filter assemblyusually requires manual cleaning by the operator, which increases thetime the filter system is offline and out of operation. Once the filtermedia and filter assembly are cleaned, the filter system is then placedback into operation until the next backwashing is desired or required.

Unfortunately, most filtration backwash systems require the filter to betaken offline and placed out of service while the backwash operation isperformed. This is due, in part, to the consistent design of filtrationsystems wherein the filter assembly does not provide an efficientmechanism for removing sedimentary solids which have accumulated at thebottom of the filter assembly. Moreover, most prior art backwash systemsrequire a secondary piping system dedicated solely to the backwashingprocess whereby backwash water is introduced and circulated in theopposite direction of normal, operational fluid flow for purposes ofremoving the accumulated solids on the filter media.

In view of the drawbacks which exist in the prior art, a need exists foran improved filter backwash apparatus that provides the ability tobackwash the filter media without requiring that the filter be takenoffline for an extended period of time. Similarly, a need exists in theart for an improved filter backwash apparatus which can provide a quick,efficient flushing mechanism to remove sedimentary solids which haveaccumulated in the filter assembly.

Accordingly, it is an object of this invention to provide a backwashablefilter assembly which does not require the cessation of filteroperations for an extended period of time during the backwashingprocess. It is further an object of this invention to provide abackwashable filter system that does not require a secondary pipingsystem dedicated to backwashing operations. It is further an object ofthis invention to provide a backwashable filter assembly thatincorporates an efficient flushing mechanism which results in theremoval of solids from the filter media and the removal of sedimentarysolids which have collected at the bottom of the filter assembly. It isfurther an object of this invention to perform these multiple functionsin a single, one-quarter turn movement to initiate the backwash process,and to return to normal filter operations in a reverse single,one-quarter turn movement. It is a further object of this invention toprovide a backwash, flushing filter with a unique flat seal around theinlet and outlet ports to minimize fluid “blow-by” during filter andbackwash operations. It is further an object of this invention toprovide a unique application of a dual tab-lock and sealing mechanismallowing for the operation and backwash operation of the filter unitdisclosed herein without leakage between moving components. It is afurther object of this invention to incorporate a unique mechanism forretaining a gasket seal located near the backwash fluid drain port whichretains the seal in place during the fluid turbulence generated duringbackwash operations. It is a further object of this invention toincorporate a unique filter assembly design that utilizes a slot designto capture accumulated solids by reducing fluid turbulence and yetprovide for effective backwash operations. Further objects of thisinvention will be apparent to persons knowledgeable with devices of thisgeneral type upon reading the following description and examining theaccompanying drawings.

SUMMARY OF THE INVENTION

In accordance with the foregoing objects, the present invention—aself-cleaning, backwash flushing filter system—generally comprises asystem inlet; a filter assembly, a backwash drain pipe and a filteredfluid outlet in selective fluid communication with the system inlet.

The preferred embodiment of the present backwash flushing filterassembly invention comprises a header assembly, a rotatable valveassembly, a filter element assembly, and a filter housing assembly. In asingle operation, the controller moves the turn knob on the rotatablevalve assembly a one-quarter turn to reverse the flow of fluid throughthe filter assembly, including the filter element assembly. Any debrisremoved from the filter element media during the backwash process areimmediately discharged from the system through the drain port located inthe bottom portion of the filter housing. The hydraulic shearingmechanism of the backwash fluid breaks up and dislodges any debris whichhave accumulated on the filter media and at the bottom of the filterassembly during normal filter operation, which are then removed from thefilter assembly through the backwash drain port. The controller thenreturns the filter assembly operation to filtration operation by areverse one-quarter turn of the turn knob, which again reverses thefluid flow through the filter assembly and normal filtration operationcommences once again.

Many other features, objects and advantages of the present inventionwill be apparent to those of ordinary skill in the relevant arts,especially in light of the foregoing discussions and the followingdrawings, exemplary detailed description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself, however, as well asa preferred mode of use, further objectives and advantages thereof, willbe best understood by reference to the following detailed description ofillustrative embodiments when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of the backwash flushing filter assemblyembodying the invention disclosed herein;

FIG. 2 is a fragmentary view of the components of the backwash flushingfilter assembly embodying the invention disclosed herein;

FIG. 3 is a profile cross-sectional view of the backwash flushing filterassembly shown in the assembled mode;

FIG. 4A is a top cross-sectional view of the rotatable valve assemblyshown in standard filter operation mode;

FIG. 4B is a profile cross-sectional view of the backwash flushingfilter in standard filter operation;

FIG. 4C is a top cross-sectional view of the rotatable valve assemblyshown in filter backwash operation mode; and,

FIG. 4D is a profile cross-sectional view of the backwash flushingfilter in filter backwash operation mode.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment of the invention disclosed herein as shown inFIGS. 1-4D is a backwash flushing filter assembly 10 whereby switchingfrom filtration mode to backwash flushing mode is performed by aone-quarter turn of the rotatable valve assembly and vice versa asdiscussed in further detail below.

FIG. 1 depicts the assembled backwash flushing filter assembly 10 withconnection points to a fluid source pipe 12, filtered fluid outlet pipe14, and backwash drain pipe 16. The filter assembly 10 is preferablyconstructed so that the filter assembly 10 can be readily accessed topermit visual component inspection, filter media removal andreplacement, if necessary. The filter assembly 10 can be constructed ina variety of sizes to accommodate both standard and custom filterelement sizes and uses as known in the art.

Turning now to FIG. 2, the backwash flushing filter assembly 10 is shownin exploded view. Filter assembly 10 is comprised of a header assembly20, a rotatable valve assembly 30, a filter element assembly 40, and afilter housing assembly 50. In further detail, the header assembly 20 iscomprised of a cylinder cap 21 and cylinder base 22 which includesthreaded connector means within the interior circumference of cylinderbase 22. A fluid inlet connect 23 is formed as part of cylinder cap 21and provides for the inflow of fluid into the backwash flushing filterassembly 10. The filtered fluid outlet connect 24 is formed as part ofcylinder cap 21 and is oriented, in the preferred embodiment, oppositeof fluid inlet connect 23, although other configurations may be utilizeddepending on the application. Filter fluid outlet connect 24 provides anoutlet for fluid that has been filtered by the filter assembly 10. Setclip 25 is removably inserted into and through the cylinder cap 21 via apreformed slot in cylinder cap 21 as shown. In this embodiment, set clip25 is utilized to retain the rotatable valve assembly 30, described indetail below, within the header assembly 20 during filter and backwashoperations. An alternative embodiment of the present invention mayinclude one or more independent pins which are inserted throughpreformed holes in the cylinder cap 21 as the retention mechanism forthe rotatable valve assembly 30. Likewise, additional means for securingthe rotatable valve assembly within the header assembly may includethreaded screw-type connections, tongue-in-groove connections andlocking tabs in various orientations to accomplish the retentionobjective and allowing for the insertion and removal of the rotatablevalve assembly 30 from the header assembly 20.

The rotatable valve assembly 30 includes a turn knob 31, two sealgaskets 32, a backwash fluid inlet port 33, a filtered fluid outlet port34, a top filter coupler 35, and a turn guide slot 36 which is preformedinto the rotatable valve assembly 30 below the turn knob 31 as shown inFIG. 2. Rotatable valve assembly 30 includes an interior chamber 38which during filter operations receives filtered fluid from the filterelement assembly 40 and allows for the passage of filtered fluid to thefluid filter outlet port 34. During backwash mode, backwash fluid isdelivered into the interior chamber 38 of the rotatable valve assembly30 via backwash fluid inlet port 33 which then flows in the reversedirection down through the filter element assembly 40 and results in thebackwashing of same. Seal gaskets 32 minimize fluid “blowby” when thefilter assembly 10 is switched from filter operation to backwashoperations and vice versa and also maintains segregation of theunfiltered inlet fluid, filtered fluid and backwash fluid during filterand backwash operations.

Filter element assembly 40 is comprised of a filter stalk 41, filterports 42, filter media or mesh 43, lower filter coupler 44 with athreaded gasket stem 45, a gasket seal 46, and gasket cap 47. In thedisclosed embodiment, filter stalk 41 is a cylindrical pipe having firstand second open ends. The first or lower open end is sealably connectedto lower filter coupler 44, while the second or upper open end issealably connected to the interior cavity of the rotatable valveassembly 30 via the top filter coupler 35 and releasably locked intoplace by locking tabs or pin 37. Gasket seal 46 is releasably connectedto lower filter coupler 44 by placement around gasket stem 45 andretained by screwing on gasket cap 47 via the threaded exterior ofgasket stem 45. Alternative embodiments of the filter element assemblymay include a barb gasket stem, instead of a threaded gasket stem, whichallows the user to simply slip gasket seal 44 over the barbed end of thegasket stem which thereby retains the gasket seal 44 in a securedposition. Additional connection means for retaining gasket seal 44 togasket stem 45 maybe employed as required by the particular applicationor operating environment. Filter element assembly 40 is therebyreleasably secureable within filter housing assembly 50. The lowerfilter coupler 44 may also include preformed slots or surfaceindentations which act to minimize fluid turbulence during filteroperation mode, thereby aiding in the capture and sedimentation ofaccumulated solids at the bottom end of the filter assembly 50.

Filter housing assembly 50 is comprised of a filter housing 51, aheader/filter body threaded connect 52, a backwash drain port connect53, and a backwash fluid drain port 54. Filter housing assembly 50 iscylindrical in shape and, in the embodiment shown, is composed of afilter housing 51 with an open upper end and a lower end with a reduceddiameter in appropriate relation to the diameter and length of filterelement assembly 40. The lower end of filter housing assembly 50includes a threaded backwash drain connect 53 and open backwash drainport 54 as depicted in FIG. 2.

FIG. 3 shows an assembled version of the backwash flushing filterassembly 10. In the preferred embodiment, the rotatable valve assembly30 is slidably disposed within the header assembly 20. Filter elementassembly 40 is releasably attached to the rotatable valve assembly vialocking tab 37. The filter housing assembly 50 is releasably secured tothe header assembly 20 via threaded connects 52. After assembly in thismanner, the filter assembly 10 is ready for placement in an operationalenvironment.

A plurality of pipes may be connected to the filter assembly 10 forintroducing fluids into and removing fluids from the filter assembly 10.In the present embodiment, a fluid source pipe 12 and a filter fluidoutlet pipe 14 are connected to the filter assembly 10, via fluid inletconnect 23 and fluid outlet connect 24, respectively, so as tocommunicate with the interior of the header assembly 20, rotatable valveassembly 30, filter element assembly 40, and filter housing assembly 50.The fluid source pipe 12 is used to introduce an unfiltered inlet fluidto be filtered into the header assembly 20 and filter housing assembly50 from an un-illustrated source, the filtered fluid outlet pipe 14transports filtered fluid downstream, and the backwash drain pipe 16 isused to remove unwanted debris suspended in the backwash fluid from thefilter element assembly 40 and filter housing assembly 50 via backwashdrain port 54.

Turning to FIG. 4A, a cross-sectional top view of the rotatable valveassembly 30 is shown in the filtration mode position. In this view,regular filter operation is ongoing and the backwash fluid inlet port 33is shown in the closed position and filter fluid outlet port 34 is shownin the open position. As shown in FIG. 4B, inflow fluid to be filteredenters the filter assembly 10 through fluid inlet connect 23 andcirculates into the filter housing assembly 50 and contacts the filterelement assembly 40. As the inflow fluid continues to circulate,suspended solids within the inflow fluid contact filter media 43. Atthis point, solids of a predetermined size are prevented from passingthrough filter media 43 while the newly filtered fluid then passes intoand up through the filter stalk 41 via filter ports 42 due to thepressure differential between the incoming fluid from fluid source pipe12 which is under a greater pressure than the fluid pressure present inthe filtered fluid outlet pipe 14. Due to the hydraulic differential,the filtered fluid then moves into the interior cavity 38 of therotatable valve assembly 30 and exits the interior cavity 38 via filterfluid outlet port 34 and into filter fluid outlet pipe 14. As thefiltration process continues, suspended solid matter will begin toaccumulate on filter media 43 and begin to form a sediment deposit atthe bottom of the filter housing assembly 50 between the filter elementassembly 40 and the filter housing filter housing 51. In turn, thiscauses the efficiency of the filtering process to decline to a point atwhich the controller initiates the filter backwash operation.

Turning to FIG. 4C, a cross-sectional top view of the rotatable valveassembly 30 is shown in the backwash mode position. In order to initiatebackwashing operations, the rotatable valve assembly 30 is turned aone-quarter turn by manipulation of the turn knob 31. This causes thefilter fluid outlet port 34 to be placed in the closed position and thebackwash fluid inlet port 33 to be in the open position, which thenresults in connection with fluid inlet connect 23 which is incommunication with fluid source pipe 12. Fluid is introduced via fluidsource pipe 12 into the interior chamber 38 of the rotatable valveassembly 30 and proceeds down into the interior of the filter stalk 41.At the same time, due to the inclined slot 36 into which the set clip 25is positioned, by turning turn knob 31 a one-quarter turn, the rotatablevalve assembly 30 and filter element assembly 40 proceeds to moveaxially within the header assembly 20 and filter housing assembly 50,which results in the filter element assembly 40 being disconnected fromsealed contact with the filter housing 51 via gasket seal 46 whichresults in the creation of a pressure differential between the fluidsource pipe 12 and the backwash drain port 54. As a result, backwashfluid flows from the interior of filter stalk 41 via filter ports 42 andback through filter media 43. This reversal of fluid flow results in ahydraulic shearing mechanism by which suspended solids 60 are washedaway from the filter media 43 and exit filter element assembly 40 viabackwash drain port 54. Likewise, the reversal of fluid flow through thefilter element assembly 40 creates a “flushing” action which erodes andremoves, via backwash drain port 54, any sedimentary build up that hascollected at the bottom of the filter housing assembly 50 between thefilter element assembly 40 and the filter housing filter housing 51.During the backwashing cycle, the gasket seal 46 is securely held inplace around the gasket stem 45 by gasket cap 47 thereby preventing thegasket seal 46 from becoming dislodged and blocking the backwash drainport 54 during backwash operations by the fluid turbulence generatedduring backwash operations.

After the backwash operation is complete, the controller turns turn knob31 a reverse one-quarter turn. This results in the filter fluid outletport 34 returning to the open position and the backwash fluid inlet port33 to be placed in the closed position. Fluid to be filtered once againenters the filter assembly 10 through fluid inlet connect 23, circulatesinto the filter housing assembly 50 and contacts the filter elementassembly 40 as previously discussed. At the same time, due to theinclined slot 36 into which the set clip 25 is positioned, by turningturn knob 31 a reverse one-quarter turn, the rotatable valve assembly 30and filter element assembly 40 move axially in the reverse direction andenter into sealed contact with the filter housing 51 via gasket seal 46which results in the creation of a pressure differential between thefluid source pipe 12 and the filtered fluid outlet pipe 14. The fluidthen contacts the filter media 43 resulting in the removal of suspendedsolids and the filtered fluid then moves into the interior volume of thefilter stalk 41, then into the interior chamber 38 of the rotatablevalve assembly 30 and exits the rotatable valve assembly 30 via thefiltered fluid outlet port 34.

An additional feature of the invention disclosed herein allows for thesimple and quick removal and replacement of the filter media 43, withoutthe need to remove the entire filter assembly 10 from the piping system.To change the filter media 43 or filter stalk 41, the user may simplyshut off fluid communication to the filter assembly 10, pull set clip 25out of the header assembly 20 and remove the rotatable valve assembly 30and filter element assembly 40 from the filter housing assembly 50. Theuser can then remove and reinstall change the filter media or an entirefilter stalk as the need arises. The user then reassembles the filterassembly 10 in the reverse order of the steps outlined above,reinitiates fluid communication with the filter assembly 10 and resumesfilter operations.

The backwashing filter apparatus and method disclosed herein are subjectto application and modification by those of ordinary skill in the art.Although the present invention has been described in terms of anexemplary embodiment, it is not limited to these embodiments andmodifications. Alternative embodiments, modifications, and equivalents,which would still be encompassed by the invention, may be made by thoseof ordinary skill in the art, in light of the foregoing teachings.Therefore, the following claims are intended to cover any alternativeembodiments, modifications, or equivalents which may be included withinthe spirit and scope of the invention defined by the claims.

1. A backwash, flushing filter assembly comprising: a header assemblywherein the header assembly includes a cylinder cap, a cylinder basewith threaded connector means disposed within the interior circumferenceof the cylinder base, a fluid inlet connect and a filtered fluid outletconnect; a rotatable valve assembly which is slidably connected to theheader assembly wherein the rotatable valve assembly includes aninterior chamber with a backwash fluid inlet port, a filtered fluidoutlet port, and at least one seal gasket; a filter element assemblywhich is releasably connected to the rotatable valve assembly whereinthe filter element assembly includes, a filter stalk with filter portsformed in the filter stalk, and a filter media disposed around theexterior of the filter stalk; and, a filter housing assembly which isreleasably connected to the header assembly wherein the filter housingassembly includes a filter housing and a backwash drain port.
 2. Theassembly of claim 1 wherein the header assembly and filter housingassemblies are detachably connected via threaded connects.
 3. Theassembly of claim 1 wherein a set clip is inserted through the cylindercap and mates to the slot in rotatable valve assembly for releasablysecuring the rotatable valve assembly and filter element assembly withinthe filter housing assembly.
 4. The assembly of claim 1 wherein therotatable valve assembly further includes a turn knob and a turn guideslot formed on the exterior circumference of the rotatable valveassembly.
 5. The assembly of claim 1 wherein the rotatable valveassembly further includes a top filter coupler.
 6. The assembly of claim1 wherein the filter element assembly further includes a lower filtercoupler.
 7. The assembly of claim 1 wherein wherein the filter stalk isreleasably connected to the rotatable valve assembly via the top filtercoupler by locking pins.
 8. The assembly of claim 1 wherein wherein theupper end of the filter stalk is releasably connected to the rotatablevalve assembly via the tip filter coupler by locking tabs.
 9. Theassembly of claim 1 wherein the lower end of the filter stalk isreleasably connected to the lower filter coupler.
 10. The assembly ofclaim 1 wherein the lower filter coupler includes a gasket stem.
 11. Theassembly of claim 10 wherein a gasket seal is placed around the gasketstem of the lower filter coupler and detachably secured thereto by agasket cap.
 12. The assembly of claim 10 wherein the lower filtercoupler gasket stem and gasket cap are releasably connected via threadedmeans.
 13. The assembly of claim 1 wherein the filter stalk ports areformed circular shape slots in the filter stalk.
 14. The assembly ofclaim 1 wherein the filter stalk ports are formed rectangular slots inthe filter stalk.
 15. The assembly of claim 1 wherein a removable setclip detachably secures the filter housing with the rotatable valveassembly.
 16. A method for backwashing an inline filter assemblycomprising the steps of: providing the filter assembly of claim 1;directing a fluid into the filter assembly; filtering the fluid througha filter media disposed on the exterior surface of a filter stalk;turning the rotatable valve assembly which results in the reversal offluid flow through the filter stalk; removing the debris on the filtermedia and at the bottom of the filter housing assembly via the backwashdrain port.
 17. The method of claim 16 wherein initiating the backwashoperation is accomplished by a one-quarter turn of the rotatable valveassembly.
 18. The method of claim 16 wherein the filter element assemblyis separated from contact with the lower filter coupler gasket seal andthe collected solids are removed via the backwash drain port during thebackwash operation.
 19. The method of claim 16 wherein the backwashoperation is terminated by turning the rotatable valve assembly by anopposite one-quarter turn resulting in the resumption of filteroperation.
 20. A backwash, flushing filter assembly comprising: a headerassembly wherein the header assembly includes a cylinder cap, a cylinderbase with threaded connector means disposed within the interiorcircumference of the cylinder base, a fluid inlet connect, a filteredfluid outlet connect and a removable set clip; a rotatable valveassembly which is slidably connected to the header assembly wherein therotatable valve assembly includes an interior chamber with a backwashfluid inlet port and a filtered fluid outlet port, a top filter couplerand a turn guide slot; a filter element assembly which is releasablyconnected to the rotatable valve assembly wherein the filter elementassembly includes a lower filter coupler, a filter stalk with filterports formed in the filter stalk, and a filter media disposed around theexterior of the filter stalk; and, a filter housing assembly which isreleasably connected to the header assembly wherein the filter housingassembly includes a filter housing and a backwash drain port.
 21. Theassembly of claim 20 wherein the removable set clip is inserted througha preformed slot in the cylinder cap thereby securing the rotatablevalve assembly and filter element assembly within the filter housingassembly.
 22. The assembly of claim 21 wherein as the rotation of therotatable valve assembly results in the axial movement of the rotatablevalve assembly and filter element assembly.
 23. The assembly of claim 20wherein rotation of the rotatable valve assembly reverses the directionof fluid flow through the filter.
 24. The assembly of claim 20 whereinthe rotation of the rotatable valve assembly reverses the direction offluid flow through the filter assembly and flushes the collected solidsfrom the bottom of the filter housing assembly.
 25. The assembly ofclaim 20 wherein the lower filter coupler includes preformed slots onthe exterior surface of the lower filter coupler to assist in thecapture of accumulated solids.
 26. The assembly of claim 20 wherein thelower filter coupler is removably connected to the filter stalk.
 27. Amethod for replacing an online filter element assembly comprising thesteps of: removing a set clip from a header assembly: pulling a filterelement assembly out of a filter assembly; replacing the filter media;and, inserting the filter element assembly into the filter assembly;and, inserting the set clip into the header assembly.
 28. The method ofclaim 27 wherein the replacement of the filter element assembly isaccomplished without detaching the filter assembly from an influentpipe.
 29. The method of claim 27 wherein the replacement of the filterelement assembly is accomplished without detaching the filter assemblyfrom an effluent pipe.
 30. The method of claim 27 wherein thereplacement of the filter element assembly is accomplished withoutdetaching the filter assembly from a backwash drain pipe.
 31. The methodof claim 27 wherein the filter media includes the filter stalk.